fix curl url

Author: chessai

.travis.yml

@@ -36,7 +36,7 @@ matrix:
     - compiler: ghc-8.2.2
       addons: {"apt":{"sources":["hvr-ghc"],"packages":["ghc-8.2.2","cabal-install-2.4"]}}
 before_install:
-  - curl -O http://arrayfire.s3.amazonaws.com/3.6.4/ArrayFire-v3.6.4_Linux_     x86_64.sh
+  - curl -O http://arrayfire.s3.amazonaws.com/3.6.4/ArrayFire-v3.6.4_Linux_x86_64.sh
   - chmod +x ArrayFire-v3.6.4_Linux_x86_64.sh
   - ./ArrayFire-v3.6.4_Linux_x86_64.sh --include-subdir --prefix=/opt
   - ls -lah /opt/arrayfire/